Annex A

AMOL I and II

Automatic Measure of Line-ups I and II: Used by automated

 

equipment to measure programme-viewing ratings.

ARP

Address Resolution Protocol. A protocol used to "resolve" IP

 

addresses into underlying Ethernet MAC addresses.

ASI

Asynchronous Serial Interface.

ASIC

Application-Specific Integrated Circuit: A customized chip designed

 

to perform a specific function.

Async

Asynchronous.

ATM

Asynchronous Transfer Mode: A connection orientated, cell based,

 

data transport technology designed for Broadband ISDN (B-ISDN).

 

It provides a circuit-switched bandwidth-on-demand carrier system,

 

with the flexibility of packet switching. It offers low end-to-end delays

 

and (negotiable on call set up) Quality of Service guarantees.

 

Asynchronous refers to the sporadic nature of the data being

 

transmitted. Cells are transmitted only when data is to be sent,

 

therefore the time interval between cells varies according to the

 

availability of data.

ATSC

Advanced Television Standards Committee: An organization

 

founded in 1983 to research and develop a digital TV standard for

 

the U.S.A. In late 1996, the FCC adopted the ATSC standard, the

 

digital counterpart of the NTSC standard.

B3ZS

Bipolar with Three Zero Substitution: A method of eliminating long

 

zero strings in a transmission. It is used to ensure a sufficient

 

number of transitions to maintain system synchronization when the

 

user data stream contains an insufficient number of 1s to do so.

 

B3ZS is the North American equivalent of the European HDB3.

Backward

Refers to hardware or software that is compatible with earlier

Compatibility

versions.

BAT

Bouquet Association Table: Part of the service information data. The

 

BAT provides information about bouquets. It gives the name of the

 

bouquet and a list of associated services.

baud rate

The rate of transfer of digital data when the data comprises

 

information symbols that may consist of a number of possible states.

 

Equivalent to bit rate when the symbols only have two states (1 and

 

0). Measured in Baud.

BER

Bit Error Rate: A measure of transmission quality. The rate at which

 

errors occur in the transmission of data bits over a link. It is

 

generally shown as a negative exponent, (e.g., 10-7 means that 1 in

 

10,000,000 bits are in error).

BISS

Basic Interoperable Scrambling System: Non-proprietary encryption

 

from EBU (Tech3290).

Bit rate

The rate of transfer of digital data when the data comprises two logic

 

states, 1 and 0. Measured in bit/s.

Block; Pixel Block

An 8-row by 8-column matrix of luminance sample values, or 64

 

DCT coefficients (source, quantized, or de-quantized).

A-2

EN/LZT 790 0005 R1A